I ended up with two shields, the first came with the gun. All the fittings were okay but there must have been a fair bit of corrosion where the strengthening bar went across. The workshop boys had cut off the strengthening bar made from angle iron, cut out the rusty plate and welded in some new plate. In this process they put too much heat into the steel and warped it.
Oh, and they also cut all the fittings off and put them to one side.
I found another shield that was nice and straight but all the fittings were rotted. I stripped this shield with the intention of using the fittings and top plate from the original shield onto this new one.
A bit of searching located the correct piece of imperial size angle iron for the strengthening bar and some more looking found some old solid rivets of the correct size and profile. So now I had everything to make one shield from the two. Now, how do I join everything together.......
Moved town, threw everything into the shed, moved house... twice.... Built a new shed, drank more coffee... drank a few beers......
Now we can fast forward to last month. After having this shield cluttering up the shed for the last three years, I thought that it was about time I worked out this problem in time to take the 25 pdr out for a display on Anzac Day.
I ended up making a few dollys for the different head sizes and profiles and, rather than a heavy bucking bar, I profiled the head shape of the rivets into a thick flat disc of metal that would rest on an anvil.
With some oxy and a few conscripts we had our first attempt at hot riveting. It took a lot longer than expected, especially trying to work out how to get the bucking bar into a few tight spots but I'm happy with the results as the joints all pulled in nice and tight.